1. Field of the Invention
The present invention relates to a car cigarette lighter which is suitable to be firmly received in different sizes of sockets.
2. Description of the Prior Art
Most cars at the present time include a cigarette lighter installed at the instrument panel thereof. FIG. 5 illustrates a conventional cigarette lighter which is substantially constructed as a cylinder 90 comprising a fuse head 901 at one end for electrical contact to a positive pole of an electric socket (not shown) on the instrument panel. Two elastic wings 91 (only one is shown) are formed on the periphery of the cylinder 90 for electrically abutting against a negative pole of the electric socket when the cylinder 90 is inserted into the electric socket. Since different cigarette lighter sockets have different sizes, the engagement between the cigarette lighter and the socket depends on the elasticity of the two wings 91. Normally, if a socket has a relatively small radius, the engagement between the lighter and the socket is relatively stronger than that between the lighter and another socket having a relatively large radius. Since the engagement between the lighter and a socket is not guaranteed solid enough, the electrical contact between the fuse head 901 of the lighter and the positive pole of the socket may be loosened due to strong shaking of the car when it travels on a poorly conditioned road.
For improving the above drawback, another cigarette lighter is provided as shown in FIG. 6. This cigarette lighter comprises a cylinder body 80 which has a head 801 formed at one end thereof and two wings 81 formed on the periphery thereof. The lighter is inserted into a socket 82 which has a positive pole 83 fixed at a bottom thereof and a negative pole 84 formed circularly around an inner surface of the socket 82. The positive pole 83 of the socket 82 is U-shaped with two elastic prongs 830 slanted at an angle with respect to a bottom plate thereof for engaging with a neck 802 from which the head 801 extends. The head 801 of the lighter is in electrical contact with the positive pole 83 and the wings 81 are electrically in contact with the negative pole 84. It appears that the construction of the lighter is suitable for all kinds of the sockets which have the U-shaped positive pole, however, in practice, the neck 802 of the lighter may damage the U-shaped pole 83 which has relatively slanted prongs, i.e., the size of the neck 802 may be suitable for some U-shaped poles with some angular range in the prongs but not for other U-shaped pole with a different angular range in the prongs.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional car cigarette lighter.